Dog door



FIG. 1 is a front, right and top perspective view of a dog door, showing our new design;

FIG. 2 is a rear, left and bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is a front, right and top perspective view of the dog door of FIG. 1 , in an alternate configuration in which the upper frame is in an open state; and,

FIG. 10 is a front, right and top perspective view of the dog door of FIG. 1 in an alternate configuration in which the upper frame is removed. 

CLAIM The ornamental design for a dog door, as shown and described. 